arm: apple: Add initial support for Apple's M1 SoC
Add support for Apple's M1 SoC that is used in "Apple Silicon"
Macs. This builds a basic U-Boot that can be used as a payload
for the m1n1 boot loader being developed by the Asahi Linux
project.
Signed-off-by: Mark Kettenis <kettenis@openbsd.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
[trini: Add MAINTAINERS entry]
diff --git a/arch/arm/mach-apple/lowlevel_init.S b/arch/arm/mach-apple/lowlevel_init.S
new file mode 100644
index 0000000..e1c0d91
--- /dev/null
+++ b/arch/arm/mach-apple/lowlevel_init.S
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * (C) Copyright 2021 Mark Kettenis <kettenis@openbsd.org>
+ */
+
+.align 8
+.global fw_dtb_pointer
+fw_dtb_pointer:
+ .quad 0
+
+.global save_boot_params
+save_boot_params:
+ /* Stash DTB pointer passed by m1n1 */
+ adr x1, fw_dtb_pointer
+ str x0, [x1]
+
+ b save_boot_params_ret